Controller for magnetic clutches.



No. 808,226. PATBNTED DEC. 26, 1905. E. H. ANDERSON.

CONTROLLER FOR MAGNETIC GLUTGHBS.

APPLICATION FILED JULY 20,1904.

Pied.

m W W R my UNITED STATES PATENT orrron.

EDWVARD H. ANDERSON, OF SCHENECTADY, NEW YORK, ASSIGNOR TO GENERALELECTRIC COMPANY, A CORPORATION OF NEWV YORK.

CONTROLLER FOR MAGNETIC CLUTCHES.

Specification of Letters Patent.

Patented Dec. 26, 1905.

Application filed July 20, 1904. Serial No. 217,312.

To all whom it may concern.-

Be it known that I, EDWARD H. ANDERSON, a citizen of the United States,residing at Schenectady, in the county of Schenectady and State of NewYork, have invented certain new and useful Improvements in Controllersfor Magnetic Clutches, of which the following is a specification.

My invention relates to controlling-switches for magnetic clutches.Magnetic clutches are peculiarly adapted for use in variable-speed powertransmission mechanisms where a source of current is available onaccount of the ease with which they may be controlled, and numerouspower-transmission mechanisms have been devised comprising a pluralityof gears controlled by different clutches so arranged that bydeenergizing one clutch or set of clutches and energizing another thespeed ratio of the driving and driven member may be changed. Oneobjection to the use of magnetic clutches for this purpose lies in theresidual magnetism which appears after a clutch has been energized. Whenthe circuit of one clutch is broken and the circuit of another clutch isclosed, the first clutch does not wholly release the gear controlledthereby; but the residual magnetism, which is very strong immediatelyafter the breaking of the circuit of a clutch, tends to keep two pairsof gears in mesh with each other, and consequently to impose unduestrains on the transmission mechanism.

The object of my invention is to provide a controlling-switch forelectromagnetic variable speed power-transmission mechanisms by means ofwhich the above objection may be eliminated.

My invention consists in providing a controlling switch withintermediate positions on either side of the running position for eachclutch or set of clutches, so that when one clutch or set of clutches isto be energized and another is to be deenergized it is necessary to passthrough an intermediate position, in which the clutch that is to bedeenergized is momentarily connected in circuit with its terminalsreversed. This sends an instantaneous flow of current through theclutch-winding in the proper direction to demagnetize the clutch and toremove allresidual magnetism.

My invention will l0est be understood by reference to the accompanyingdrawings, in which Figure 1 shows a controlling-switch arranged inaccordance with my invention and adapted for the control of anelectromagnetic variable-speed power-transmission mechanism employingfour clutches; and Fig. 2 shows one form of such a transmissionmechanism, partly in cross-section, to which my invention is applicable.

Referring first to Fig. 2, E represents a shaft carrying the fourmagnetic clutches A, B, C, and D. Four gears A, B, C, and D are looselyjournaled on shaft E, and each carries an armature a, b, 0, and (Z,adapted to be engaged by the four clutches, respectively, and thereby tobe locked to shaft E. A second shaft F carries four gears G, H, I, andJ, meshing with gears A to D, respectively.

Shaft F carries a pulley F and shaft E carries a similar pulley E. Ifpower is applied to shaft F through pulley F and if magnetwinding A isenergized, shaft E will be driven through gears G and A, and power maybe taken off from pulley E. If magnet-winding A is deenergized andwinding B energized, gear B will be locked to shaft E and shaft E willbe driven at a higher speed, due to the smaller reduction between gearsH and B. If gear A is released by its clutch, it will run idle on theshaft. If, however, clutch A has a strong residual magnetism, it willtend to hold gear A locked to the shaft, so that the two shafts F and Ewill be connected through two pairs of gears of diflerent speed ratios.This, as will be readily seen, places an undue strain on thetransmission mechanism.

Referring now to Fig. 1, K represents a controller two fingers of which,7c and are connected, through the switch S, to the line Wires or othersource of current L L for the magnet-windings of the clutches. Thefingers if to k are connected to the collectorrings a to a,respectively, the collector-rings a to (Z being connected, respectively,to one terminal of clutch-windings A to D and the fifth collector ringbeing connected to the other terminals of all the windings either bygrounding on shaft E or otherwise.

The operation of the controller K is as follows: In Fig. 1 controller Kis shown in its off position. Now if it is moved to bring the movablecontacts on the dotted line 1 into engagement with thestationarycontact-fingers a circuit is completed from line-wire L tocontact-finger Z0 contact-linger to collector-ring e, to lower terminalof magnetwinding A, through winding A, to collectorring a, tocontact-finger 7a, to contact-finger 70, to line-wire L. Theclutch-winding A is consequently energized. Position 1, however, is onlyan intermediate position, not a running position, the first runningposition beingindicatedbydottedlinel. Inpassingfrom position 1 toposition 1 it will be seen that the connections of winding A arereversed. The position 1 is of no importance when the con troller ismoved in this direction, but is of importance when the controller ismoved from position 1 to off position. In this latter movement it servesto momentarily reverse, and consequently to demagnetize, clutch A. Inpassing from position 1 to position 2 it is necessary to pass throughtwo intermediate positions. The first intermediate position 1 servestoreverse and demagnetize winding A. Position 2 is of no effect duringthis direction of movement of the controller, but serves to demagnetizeclutch B when the controller is moving in the opposite direction. Inposition 2 clutch B is energized. In passing through position 2 clutch Bis reversed and demagnetized. In position 3 clutch C is energized. Inposition 3 clutch O is reversed and deenergized. In position 4 clutch Dis energized. Thus it is seen that positions 1, 2, 3, and 1 are therunning positions for the controller. Positions 1', 2 and 3 serve todemagnetize the several clutches in moving the controller from offposition to position 1. Positions 4:, 8, 2, and 1 serve to demagnetizethe several clutches when moving from position 4 to off position. Thusno matter in which direction the controller is being moved each clutchis completely demagnetized before the circuit of another clutch iscompleted.

AlthoughI have shown my invention as applied to a plurality of clutchesarranged to connect two parallel shafts through pairs of gears withdifferent speed ratios, only one clutch being energized at a time, itwill be understood that it is not limited to this particularapplication, but may be used with advantage in any electromagneticvariablespeed power transmission mechanism in which the simultaneousenergizing of two clutches or sets of clutches would result inundesirable strains in the mechanism. Accordingly I do not desire tolimit myself to the particular construction and.arrangement of partsshown; but I aim in the appended claims to cover all such modificationswhich are within the scope of my invention.

I/Vhat I claim as new, and desire to secure by Letters Patent of theUnited States, iS-

1. In combination with a variable-speed transmission mechanismcomprising a plurality of electromagnetic clutches, a controller forsaid clutches having a plurality of running positions arranged toconnect said clutches for the several speeds, and intermediate positionsarranged to reverse" momentarily the circuit connections of each clutchwhen breaking said circuit connections in passing from one runningposition to another.

2. In combination with a variable-speed transmission mechanismcomprising a plurality of electromagnetic clutches, a controller forsaid clutches adapted and arranged to reverse momentarily the circuitconnections of each clutch when breaking said circuit connections inpassing from one position to another.

3. In combination with a variable-speed transmission mechanismcomprising a plurality of electromagnetic clutches, a source of currenttherefor, and a controlling-switch having a plurality of runningpositions arranged to connect said clutches in different relations tothe source for the different speeds, and intermediate positions on eachside of each running position arranged to connect a clutch to the sourcewith its terminal connections reversed relatively to its connections inthe adjacent running position.

In witness whereof I have hereunto set my hand this 18th day of July;190A.

EDIVARD H. ANDERSON.

Witnesses:

ALEX. F. MACDONALD, HELEN ORFORD.

